there is no perfect hemodyypnamic parameter perfect.pdf · there is no perfect hemodyypnamic...

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There is no perfect There is no perfect hemodynamic parameterhemodynamic parametery py p

Azriel Perel

Professor and ChairmanProfessor and ChairmanDepartment of Anesthesiology and Intensive CareSheba Medical Center, Tel Aviv University, Israel

Rome 2009

Disclosure

Th k t ith th f ll i iThe speaker cooperates with the following companies

BMeye

Drager-Siemens

Pulsion

[email protected]

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Hemodynamic monitoring Hemodynamic monitoring is essential for proper is essential for proper

decisiondecision--making in critically ill making in critically ill and highand high risk surgical patientsrisk surgical patientsand highand high--risk surgical patients. risk surgical patients.

And yet, each and every And yet, each and every hemodynamic variable that we hemodynamic variable that we measure has limitations and measure has limitations and

confounding factors.confounding factors.

Knowing the limitations of Knowing the limitations of hemodynamic parameters is ashemodynamic parameters is ashemodynamic parameters is as hemodynamic parameters is as

important as knowing their important as knowing their potential value.potential value.

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Clinical examinationClinical examinationBlood pressure, Heart rateBlood pressure, Heart rate

Urine outputUrine outputCVP PAOPCVP PAOPCVP, PAOPCVP, PAOPGEDV, EDAGEDV, EDA

SPV, PPV, SVVSPV, PPV, SVVCOCO

ScvOScvO22

PetCOPetCO22

SaOSaO22

EVLWEVLWMicrocirculationMicrocirculation

Clinical evaluation compared to PAC in the hemodynamic assessment of critically ill patients

Eisenberg PR et al. Crit Care Med 1984; 12: 349

Physicians correctly predict the cardiac output, Physicians correctly predict the cardiac output, PCWP and SVR in only PCWP and SVR in only 5050% of the cases% of the cases

Prediction of hemodynamics in critically ill patients by Prediction of hemodynamics in critically ill patients by clinical evaluation alone is inaccurate and unreliable.clinical evaluation alone is inaccurate and unreliable.

Assessing hemodynamic status in critically ill patients: Do physicians use clinical information optimally?

Connors AF et al. J Crit Care 1987; 2: 174

Therapeutic impact of PAC in the ICUSteingrub et al. Chest 1991; 99: 1451

PAC in critically ill patients: A prospective analysis of outcome changes associated with catheter-prompted changes in therapy

Mimoz O et al. Crit Care Med 1994; 22: 573

Hemodynamic and pulmonary fluid status in the trauma patient: are we slipping?

Veale WN Jr et al. Am Surg. 2005; 71: 621

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In patients with ALI there is a high probability that physical examination findings of ineffective

i l ti ( ill fill ti >2 kcirculation (capillary refill time >2 secs, knee mottling, or cool extremities) are not useful for predicting low cardiac index or mixed venous oxygen saturation.

In high-risk, hemodynamically stable surgical patients, there were no significant differences in mean BP, HR, urine output, and arterial oxygenation at any time between survivors and non-survivors, although non-survivors had higher lactate levels than survivors.

Adequate resuscitation cannot be based Adequate resuscitation cannot be based only on normalization of vital signs.only on normalization of vital signs.

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ScvOScvO22

PetCOPetCO22

SaOSaO22


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“Estimates of intravascular volume based on any given level of filling pressure do not reliably predict a

Crit Care Med 2006;34:1333

pressure do not reliably predict a patient’s response to fluid administration.”

We do not recommend the routine use of the PAC for patients in shockPAC for patients in shock.

We recommend that preload measurement alone not be used to predict fluid responsiveness.

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CCM 2007 35:64-8

Occult hypoperfusion! Fluid

overload!

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This systematic review demonstrated a very poor relationship between CVP and blood volume as well as the inability of CVP / ΔCVP to predict the hemodynamic response to ato predict the hemodynamic response to a fluid challenge.

CVP should not be used to make clinical decisions regarding fluid management.

Intravascular volume depletion in a Intravascular volume depletion in a 2424--hour porcine model of hour porcine model of intraintra--abdominal hypertensionabdominal hypertension

Schachtrupp A et al, J Trauma. Schachtrupp A et al, J Trauma. 5555: : 734734--740740, , 20032003

Traditional CVP cannot b d t t lbe used to accurately direct resuscitation of the critically ill patients with elevations in IAP or ITP. To do so places the patient at risk for under-resuscitation

Cheatham ML. CCM 2007; 35:1629

under-resuscitation with resultant organ dysfunction, failure, and increased mortality.

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ScvOScvO22

PetCOPetCO22

SaOSaO22


Global End-Diastolic Volume as an Indicator of Cardiac Preload in Patients With Septic Shock

F Michard et al, Chest. 2003;124:1900-1908

% of fluid-responders

720

740

760

780

800PrePre--infusioninfusionGEDViGEDVi(mL/m(mL/m22))

600

620

640

660

680

700

Responders Non-responders

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ITBV and its changes correlates to CI and its changes ITBV and its changes correlates to CI and its changes significantly better than the CVPsignificantly better than the CVP

Crit Care Med 2008; 36: 2348

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Static ‘preload’ parameters cannot Static ‘preload’ parameters cannot accurately predict the response of the accurately predict the response of the

CO to fluid loadingCO to fluid loading

F Michard et al, Chest 2003

Should we monitor preload andShould we monitor preload and fluid responsiveness in shock?

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ScvOScvO22

PetCOPetCO22

SaOSaO22


Functional hemodynamic parameters Functional hemodynamic parameters (SPV, PPV, SVV) are the most sensitive (SPV, PPV, SVV) are the most sensitive

parameters for the assessment of parameters for the assessment of

SPV PPV SVVSPV PPV SVV

Responder Non-responder

ppfluid responsiveness in mechanically fluid responsiveness in mechanically

ventilated patientsventilated patients

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Limitations and confounding factors of functional hemodynamic parameters

1. Sinus rhythm

2. Spontaneous breathing

3. Tidal volume / airway P.

4. Use in ARDS

5. SPV vs. PPV and SVV

6. The neglected dUp

7. New algorithms

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ScvOScvO22

PetCOPetCO22

SaOSaO22


Unreliability of blood pressure and heart rate to evaluate cardiac output in emergency resuscitation

and critical illness.

Wo CCJ, et al. CCM 1993;21: 218

Blood flow (cardiac output) cannot li bl b i f d f t i lreliably be inferred from arterial

pressure and heart rate measurements until extreme hypotension occurs.

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A Perel, M Maggiorini, M Malbrain, JL Teboul, J Belda, E Fernández-Mondéjar, M Kirov, J Wendon

The PiCClin StudyThe PiCClin Study

206 206 critically ill patients were evaluated by critically ill patients were evaluated by 166 166 id t did t d 146146 i li ti li tresidents and residents and 146 146 specialists.specialists.

EVLWiGEDViSVRCO

124 (40.8%)

154 (49%)

107 (34.3%)

110 (34.9%)Within ± 20%

83 (27.3%)

97 (30.9%)

46 (14.7%)

170 (54%)

Under-estimation

>20%

The main reason to measure CO is to identify patients that have low (or high) CO values that is not evident clinically, and to assess response to diagnostic and therapeutic interventions.

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Th i iti l h f SAH iThe initial phase of SAH is characterized by a high CI (5.3 L/min/m2) and a low GEDVi (555 mL/m2).

CI progressivelyCI progressively decreased and GEDVi was normalized by fluid administration aimed at normovolemia.

Cardiac output in and by itself is not

enough!

Cardiac output 6.77 L/min

ScvO2 is 60%!

Is this CO adequate???

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ScvOScvO22==7474CO

Patient is given dobutamine

ScvOScvO22==6363ScvOScvO22==7676

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CO was high, but not high enough!CO was high, but not high enough!

The limitations of cardiac output

The optimal CO for an individual patient is difficult to assess.

A low CO does not tell us WHAT to do.

A ‘normal’ or even high CO does preclude the presence of inadequate regional and microcirculatory flow.

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ScvOScvO22

PetCOPetCO22

SaOSaO22


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wns

trea

mLactate

Organ function

SvO ScvO

Upstream

CO

Hgb

CaO2

Venous oximetry Bloos, Reinhart Intensive Care Med 2005; 31:911-3

DoSvO2, ScvO2

PcvCO2

m

2

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It is useful to measure SvO2 because if cardiac output becomes inadequate, SvO2 will decrease.

A low SvO2 should prompt rapid intervention to increase oxygen delivery to the tissues.

“Clearly, SvO2 is the gold standard for defining global adequacy of

Crit Care Med 2005; 33:1119-22

g g q ycardiovascular performance.”

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A low ScvOA low ScvO22 in the perioperative period is in the perioperative period is associated with increased risk of associated with increased risk of

postoperative complicationspostoperative complications

Mixed venous oxygen saturation in critically ill septic shock patients.Krafft P, et al. Chest 1993; 103:900

Fluid resuscitation in severe sepsis and septic shock: An evidence-based review.

Vincent JL, Gerlach H. CCM 2004; 32[Suppl.]:S451

The SvOThe SvO22 of septic shock patients isof septic shock patients is mainly mainly normal or even supranormal or even supra--normal due to reduced normal due to reduced oxygen extraction.oxygen extraction.

ce t J , Ge ac CC 00 ; 3 [Supp ] S 5

Therefore, a normal or high SvOTherefore, a normal or high SvO22 does not does not necessarily indicate adequate tissue necessarily indicate adequate tissue oxygenation.oxygenation.

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Kortgen A, et al: Implementation of an evidence-based

The ScvO2 values of patients in septic shock are significantly higher than those

reported by Rivers et al (~50%)

‘standard operating procedure’ and outcome in septic shock. Crit Care Med 2006, 34:943-949.

Shapiro NI, et al: Implementation and outcomes of the Multiple Urgent Sepsis Therapies (MUST) protocol. Crit Care Med 2006, 34:1025-1032.

van Beest P, et al: The incidence of low venous oxygen saturation on admission in the ICU: a multicenter observational study in the Netherlands. Crit Care 2008, 12:R33Out of Out of 125 125 patients in septic shock only patients in septic shock only 8 8 patients (patients (66%) %) had ScvOhad ScvO22 < < 6060%, and only %, and only 1 1 ((11%) < %) < 5050%.%.

, et al,

In ICU-resuscitated patients, targeting only ScvO2 may not be sufficient to guide therapy.

When the 70% ScvO2 goal-value is reached, the presence of a P(cv-a)CO2 larger than 6 mmHg might be a useful tool to identify patients who still remain inadequately resuscitated.

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100

30405060708090

100

ScvO

2(%

)

0102030

0 2 4 6 8 10 12

LactateThe PiCClin Study

100

30405060708090

100

ScvO

2(%

)

0102030

0 2 4 6 8 10 12

LactateThe PiCClin Study

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SvOSvO22

ScvOScvO22(CVC)(CVC) Sander M, et al.

(PAC)(PAC)

S O >S O S O <S O

Gutierrez G, et al.

ScvO2>SvO2 ScvO2<SvO2

A low SvO tells you that something is wrong but

The major problems with the interpretation of ScvO2

A low SvO2 tells you that something is wrong, but not what is wrong and what should be done about it (fluids? inotropes?).

However,

When the O2ER is reduced, as is frequently the case 2 , q yin septic patients, a normal or high ScvO2 does not guarantee that perfusion is adequate and that resuscitation is complete.

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Each and every Each and every yyhemodynamic variable hemodynamic variable that we measure has that we measure has

limitations and limitations and confounding factors.confounding factors.

A number of large, randomized, prospective trials have demonstrated that protocol-based strategies can not only reduce variation and cost of ICU medicine but also improve morbidity and mortality of critically ill patients requiring ICU support.

Pathways to standardize numerous facets of patient care are becoming the most sought-after means of improving patient outcomes and reducing overall ICU expenditures.

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“Medicine has become complex. Details have become overwhelming for clinicians to process at the bedside…

Surely, we recognize the need to give up some measure of autonomy…yield some decision-making power…

The data certainly suggest that when we surrender this autonomy and standardizesurrender this autonomy and standardize care, patients do better.”

M. Levy, SCCM 2009

38th SCCM Conference Perspectives

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““In most patients with septic shock, CO will In most patients with septic shock, CO will be optimized at filling pressures between be optimized at filling pressures between

””].].2626mmHg [mmHg [15 15 --1212

Practice parameters for hemodynamic support of Practice parameters for hemodynamic support of sepsis in adults patients. sepsis in adults patients. 2004 2004 update.update.

Hollenberg et al. Crit Care Med Hollenberg et al. Crit Care Med 20042004; ; 3232::1928 1928 ––19481948

Crit Care Med 2005; 33:1119-22

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During the first 6 hrs of resuscitation, the goals of initial resuscitation of sepsis-induced hypoperfusion should include all of the following as one part of a treatment protocol:

The application of invasive monitoring data is very complex and is not easily included in therapeutic protocols that are applicable across heterogeneous populations of acutely ill patients.

Hemodynamic management is made complex because adequacy is not synonymous with “normality” and because correct application must integrate several variables…reality may be more complex than initially thought.

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The large number of critical variables and how they interact

The correct application of monitored cardiopulmonary and other variables in the critically ill is characterized by:

interact.

The importance of initial starting conditions to eventual outcome.

The effects of unexpected events.

The non-linear dynamics: Small things may have i t d t !an enormous impact downstream!

These in fact are the principles of the Complexity Theory which is used for

describing weather, traffic patterns, etc.

A therapeutic approach that targets and attempts to normalize abnormal physiological variables may be hazardous because of

Ignoring the underlying problemInducing harmAblation of physiological benefit Generation of associated errorsTraining effect

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What should we be doing?What should we be doing?

((4 4 final comments)final comments)

Hemodynamic monitoring Hemodynamic monitoring is essential for proper is essential for proper

decisiondecision--making in critically illmaking in critically illdecisiondecision--making in critically ill making in critically ill and highand high--risk surgical patients. risk surgical patients.

The fact that this statement is not The fact that this statement is not supported by EBM tells us more supported by EBM tells us more pp ypp yabout the shortcomings of EBM about the shortcomings of EBM

than those of hemodynamic than those of hemodynamic monitoring.monitoring.

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The fact that each and every The fact that each and every h d i i bl th th d i i bl th themodynamic variable that we hemodynamic variable that we measure has limitations and measure has limitations and

confounding factors has to be confounding factors has to be recognized and incorporated intorecognized and incorporated intorecognized and incorporated into recognized and incorporated into

the way we practice and teach.the way we practice and teach.

Since no hemodynamic parameter Since no hemodynamic parameter y py pis perfect, a multiis perfect, a multi--parametric parametric

approach may reduce the chance approach may reduce the chance of erroneous decisions.of erroneous decisions.

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Attempts to protocolize care in Attempts to protocolize care in critically ill patients have to leave critically ill patients have to leave

room for clinical judgment room for clinical judgment especially during especially during

th ti fli tth ti fli ttherapeutic conflicts.therapeutic conflicts.

If you meet the Buddha on the road, kill him!Sheldon Kopp

Lowe & Brydon (Printers) Ltd. 1974. ISBN 0-85969-022-9.

We must live within the ambiguity of partial We must live within the ambiguity of partial freedom, partial power, and partial knowledge.freedom, partial power, and partial knowledge.

All important decisions must be made on the All important decisions must be made on the basis of insufficient data.basis of insufficient data.

Yet we are responsible for everything we do.Yet we are responsible for everything we do.

No excuses will be accepted.No excuses will be accepted.

[email protected] you!

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